1. Field of the Invention
The present invention relates to a display device.
2. Discussion of the Background
Several kinds of display devices exist. Due to rapid development of semiconductor technology, liquid crystal displays (LCDs) having improved performance and decreased size and weight have been developed.
In an LCD, light transmittance is determined by an alignment state of a liquid crystal layer. Because light transmittance is adjusted by physical movement of the liquid crystal layer, the LCD may have a problem in terms of response speed.
Blue phase liquid crystal that has a relatively fast response speed of about 3 μm has been developed. Because blue phase liquid crystal has a very narrow operating temperature range, a crystal structure thereof may be stabilized by adding a monomer and polymerizing.
When an electric field does not exist, blue phase liquid crystal has optical isotropy, exhibits a blue phase, and does not have birefringence. In this state, if an electric field is applied to the blue phase liquid crystal, it has optical anisotropy and birefringence. In this case, an electric field that is applied to the blue phase liquid crystal is applied in a substantially horizontal direction. Here, the horizontal direction indicates a direction parallel to a pair of substrates that are disposed opposite to each other with blue phase liquid crystal disposed therebetween. An electric field is applied to the blue phase liquid crystal through an electrode in the substrate.
However, a display device using blue phase liquid crystal may have a relatively high driving voltage and deteriorated light transmittance.
Accordingly, by protruding an electrode from a substrate in a direction perpendicular to the substrate, a strong horizontal electric field, which is applied to the blue phase liquid crystal, may be formed, whereby the driving voltage may be lowered.
However, it may be difficult to stably protrude an electrode. Specifically, it may be difficult to accurately align the electrode when forming the protruded electrode. If the electrode is not properly aligned, the horizontal electric field may be weak, and therefore, the driving voltage may not decrease even when the protruded electrode is used.